The invention relates generally to a track chain for a track laying work machine and, more particularly, to a cartridge assembly for a track chain assembly.
Track laying work machines utilize articulating track chains for propelling the work machines over the terrain during operation. Such track chains operate in extremely adverse environments in which track joints may be exposed to various abrasive mixtures of water, dirt, sand, rock or chemical elements and to wide temperature ranges varying from high heat in deserts and extreme cold in artic regions. Consequently, seals are placed in the track joints and must be maintained to ensure that the seal will effectively exclude contaminants and retain lubricant during use.
Typical track chain designs typically include a track pin either rotatably or fixed to a pair of chain links and have a bushing rotatably positioned between the links and about the track pin. These designs have included a variety of seal configurations and positions such as against an inside face of the link or against the track bushing. One prior art design that uses a sealed and lubricated cartridge assembly for the track pin and bushing arrangement namely U.S. Pat. No. 6,382,742 for a xe2x80x9cCartridge Assembly for a Track Chain of a Track Type Work Machinexe2x80x9d, issued May 7, 2002 to Hasselbusch et al., and assigned to the assignee of the present application, has greatly improved the retention of lubrication and the exclusion of contaminants. This cartridge assembly includes a bushing having a stepped passage rotatably positioned about a track pin. A pair of rotatable bearing members are positioned adjacent each end face of the bushing. The bearing members and the bushing are retained by a pair of collars that are press fit and laser welded to the ends of the track pin. A seal groove is positioned in each end of the bearing members in which a seal arrangement is placed. The seal arrangement pushes against the end faces of the track bushing and the end faces of the collars. However, keeping the seal area free from contaminants and the positioning of the seals is critical to the design.
The present invention is directed to overcoming one or more of the problems as set forth above.
In one aspect of the present invention a cartridge assembly for a track chain is provided. The cartridge assembly includes a track pin, a bushing, bearing members and collars. The track pin defines a longitudinal axis and has a bore positioned therethrough. The bushing has a pair of end faces and a passage is defined therethrough and is rotatably positioned about the track pin. The bearing members have a first end portion, a second end portion and a bore is defined therethrough. The bearing members are positioned about the track pin so that the second end portion of each of the bearing members is adjacent to the bushing. The collars have a first end portion, a second end portion and a bore defined therethrough. The collars are positioned about the track pin so that the second end portion of each of the collars is adjacent the first end portion of each of the bearing members. A first seal arrangement is positioned in at least one the pair of end faces of the bushing and the second end portion of each of the bearing members. A second seal arrangement is positioned in at least one of the first end portion of each of the bearing members and the second end portion of each of the collars.